Veneer-drying apparatus.



F. BISHOP. VENEER DRYING APPARATUS. APPLICATION men 950.19. 1914.

Patented May 16, 1916.

2 SHEETS-SHEET l F. BISHOP. VENEER DRYING APPARATUS. APPLICATION FILEDDic. 18. 1914.

Patented May16,1916.

2 SHEETS-SHEET 2.

1 IDI L WIT/VESSES:

'mE COLUMBIA PLANoaR/PH co., WASHING-run'. D. c

narran sTaTns TaTnnT oTTTea FRANK BISHOP, O-F CAIRO, ILLINOIS, ASSIGNORTO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

VENEER-DRYING APPARATUS.

Specification of Letters Patent.

Patented May 16, 1916.

Application filed December 18, 1914. Serial No. 877,867.

To all fnv/tom t may concern:

Be it known-that I, FRANK BIsHor, a citizen of the United States,residing' at Cairo, in the county of Alexander and State of Illinois,have invented; certain new and useful Improvements in Veneer-Drying`Apparatus, of which the following is a specification, reference beinghad therein to the accompanying drawings.

This invention relates to an improvement in drying apparatus, moreparticularly of that class designed for drying wood veneers, and it hasfor some of its objects to produce a uniform drying action throughoutall parts of each veneer, to effect the drying operation with a minimumamount of heat, and to thus re-duce the cost of the drying operation. l

The present invention is designed particularly for use in connectionwith that class of drying apparatus-forming the subject of the UnitedStates patents to A. S. Nichols, No. 515,357, of February 27, 1894, andNo. 918,581, of April 20, 1909, comprising a series of separable platenswith means for applying heat thereto and means for alternatelyseparating and closing together said platens with the veneers supportedbetween them so as to apply to their opposite faces alternately heatedsurfaces and air currents designed to approximate uniform dryingconditions. The improvement is, however, obviously adapted foremployment in connection with other types and varieties of dryingapparatus. Y

It has been customary heretofore to set up one or more of such dryingapparatus in a room or compartment sufficiently large not only tocontain all of the operative parts, but to permit the entrance ofattendants engaged in introducing and removing the veneers for thesuccessive drying operations.

According to the present improvement the supporting and heating meansfor the veneers or other objects to be dried are closely embraced by andhoused within a closed casing having preferably detachable insulatedwallswith means for access to its interior at one end of the veneers. Bythus covering the drying means by a suitable insulated housing, themoistureaescaping from the veneer in the drying operation is retainedwithin the same so as to prevent eX- cessively rapid Adrying and theconsequent splitting of the end portions of the veneers.

The radiation of heat from the outer faces of the platens is also verymaterially reduced, and consequently the steam pressure can becorrespondingly reduced so as to effeet equally rapid drying with muchless liability to damage of the veneer and less steam consumption thanwith drying apparatus lacking such housing.

Where several drying4 apparatus are grouped together in the same room orcompartment, the radiation from the heating elements -makes thetemperature of the atmosphere in such room or compartment almostunbearable for-the attendants, especially in the summer season, forwhich reason it is diiiicult to maintain proper attendance to insureuniform production. By means of ythe present improvement, the attendantsare protected from the drying hea-t, excepting in the intervals duringwhich the casing is open for admission and withdrawal of the veneers orother objects. In the class of drying apparatus referred to, theseparable platens have been connected with and moved into and out ofContact relation with the interposed veneers by means of reciprocallymovable hydraulic presses which are disposed, according to the presentimprovement, exterior to the housing. By this means, the cylinders ofsaid presses are disposed in an atmosphere at normal temperatures, andare protectedfrom the intense heat within the casing, thereby involvinga material saving in packing.

The invention will be understood by reference to the accompanyingdrawings, in whichy Figure 1 is a front elevation of a drying apparatusembodying the present improvements, and Fig. 2 a side elevation of thesame, portions of the casing being omitted to expose the veneersupporting and drying means within the same. Fig. 3 is a detailsectional view showing the construction of the side walls and doors ofthe casing and their manner of application to the frame work, and Fig. 4is a similar view of adjacent portions of the upper and lower doors bywhich access is provided to the interior of the casing.

The main frame of the apparatus comprises the vertical columns 1, thecompound crossbeams 2 connecting the upper ends of the same and thetie-bars 3 connecting the lower portions thereof. Resting upon the topsof the beams 2 are the pivotal studs 4 Vprojecting oppositely from theupper ends of the swinging link-bars 5 depending between the componentmembers of the bea-ms 2 and pivotally connected at the lower ends bymeans of bolts 6 with the upper ends of the hollow platens 7 suitablyconstructed in practice for circulation of steam or other heating fluidby which the platens may be maintained in heated condition. Suspended bymeans of bolts 8 from one of the beams 2 are the stirrups 9 supportingthe header 10 from which depend a series of supply pipes 11 (one only ofwhich is shown in F ig. 1), connected at the lower ends with the steamcirculation spacer within the respective platens. The header 10 isconnected by means of the pipe 12 with a suitable steam supply.Connected with the steam circulating means at the lower end of eachplaten are the drip pipes 13 leading into the header 14 supported by thestirrups 15 depending from one of the tie-bars 3 and provided with theoutlet pipe 16.

The platens at the opposite ends of the series are connected with theplunger-rods 17 of alined hydraulic presses comprising the cylinders 18which are in practice suitably supported upon the columns or standards 1and provided each with water supply and discharge pipes 19 and 20, asrepresented more fully in the said Patent No. 918,581. By means of thesehydraulic presses, pressure is applied and relieved between the endplatens and the adjacent platens, Kthe series of platens being pref*erably connected together to move toward and from each other by means oflazy-tongs connections, as represented insaid patent.

:Disposed intermediate the end columns 1 of the main frame are thecorner posts or standards21 of an auxiliary housing frame which areconnected together at the bottoms by means of the cross-beams 22, and inthe upper portions on opposite sides 4by the cross-beams 23. extendingbeneath the beams 2. These standards are connected at the upper endsatthe front and back by means of the cross-beams 24, which arerespectively forwardly and rearwardly offset and sustainrthe groovedpulleys 25 by means of the studs-26. Thestandards 21 are also connectedat the sides in Ytheir lower portions by the cross-beams `27 which arein turn connected intermediate'their ends with the upper cross-beams V23bythe upright posts Orstandards 28.

Detachably ksecured to the sides of the auxiliary frame are `the fhollowinsulated panels 29 and 30, the latter being ,provided in-.one edge witha `notch 30 to receive l'the plunger-rod 18, `and beneath `the Isame isalower Apanel 31 formed in its opposite edges with "notches 32 .toreceive the tie-bars 3. Banels .-33 ,and` 34 falte :appli-ed to theupper and'lower portions of the frame at the front and back with anintermediate opening for access to the forward and rearward edges orends of the platens 7 and the veneer spaces between them. The top of thecasing is closed by means of the panels 35 and 36 resting upon thecross-beams 23 between the main-frame beams 2.

Secured upon the outer faces of the angleiron standards 21 at the frontand back of the casing by means of bolts 37 (Fig. 3) are kguide-strips38 separated therefrom by means of the spacing strips 39 to affordchannels or runways to receive the lateral ianges 40 of-the hollow upperand lower doors 41 and 42. These doors are provided respectivelyadjacent their ends with the straps 43 and 44 provided at their upperends with eyes 45 in which are securedthe opposite endsof the cords orcha-ins 46 passing over the pulleys 25 affording supports for the doorswhich are thus counter-balanced. The upper doors are provided centrallywith the handles 47, and the lower doors have secured thereon thedepending straps 48 provided at their lower ends with lateral extensions49 affording stirrups for the feet of the attendants when opening thedoors for accessto the interior of the casing.

The several panels of the casing are made of hollow construction, eachpreferably comprising `a flat outer plate 50 and an inwardly recessedinner plate 51 having lateral flanges `extending entirely around thesame and secured to the marginalrportions of the outer plate, asrepresented Lparticularly in Fig. 3. The doors are shown in said figure,similarly constructed, excepting that the inner plate 52 is fiat and theouter plate 53 is outwardly recessed with its marginal'flanges securedupon the marginal portions ofthe inner plate, and the end flangesbeingembraced by the runways aorded between the standards 21 andguide-strips 38. The adjacent flanges of the doors are shown in F ig. 4-strengthened by means of the angie-irons 54 secured thereon by means ofrivets. The hollow walls of the casing, as thus constructed, arepreferably lled with insulating substances commercially knownas"asbestocel, air cell or nonpareil insulation, or combinations thereofbest suited to the several parts of the apparatus.

The 1several component members of the auxiliary frame are shown providedwith externally projecting stud-bolts 55 secured in position by means oflock-nuts 55. Overlapping `the `outer faces of the auxiliary framemembers adjacent such stud-bolts are the flanges constituting the thinmarginal portions of the several insulated panels. Thesemarginal-portions are forcibly pressed upon Ythe respectiveframemem-bers by means of the arched clamp members 56 h-avingone extremityresting thereon and ,the other resting upon another of such marginalportions or upon the frame member, while the intermediate portion isapertured to receive the stud-bolt, a thumb-nut 57 being applied to thethreaded outer portion of the studbolt for'forcing the clamp-member uponthe panel. The hollow insulated portion of each panel projects inwardlyand is so proportioned as to fit loosely between the adjacent framemembers by means of which it is laterally positioned suitably forreceiving the clamping members 56.

The component members of the crossbeams 2 are spaced apart to afford alongitudinal slot to receive the upper portions of the platen-supportinglinks 5, and this opening is covered by means of the sheet-metal cap 58which is recessed to receive the upper ends of the links 5 and securedupoh the top of the beam 2 by means of tap-bolts 59.

The housing, as thus described, presents wall-s which effectivelyconfine the heat within a comparatively small space surrounding theveneers, so as to not only economize heat but to retain the moistureescaping from the veneers for preventing the too rapid drying of themore exposed parts of the latter. By the employment of the clamps forsecuring the panels detachably in position, the latter may be readilyremoved from the auxiliary frame for cleaning and repairs. Thecounter-balanced doors at the front and back of the casing are easilyand quickly forced apart by the attendants grasping the handle 17 withthe hand and pressing the stirrup 49 by the foot in opening the same andas readily closing the same by drawing down the upper door by means ofits handle.

In the use of the apparatus, the sheets of veneer are usually insertedthrough the front and rear doors of the casing at each end and betweenthe platens, in case they are sufficiently short, and the hydraulicpresses are set in action by automatic operation of alternately openingand closing hydraulic valves connected with the hydraulic presscylinders18 by means of suitable apparatus, such for instance as that shown anddescribed in the aforesaid United States Patent No. 918,581. The openingand closing of the platens usually takes place at intervals of ten totwenty seconds depending upon the thickness of the veneers, theprincipal object of this frequent opening and closing or breathingaction being to allow for the contraction of the veneer and consequentprevention of splitting that would be liable if the veneer weremaintained tightly clamped between the platens throughout thedryingprocess. This action is allowed to continue for a period of ten totwenty minutes, depending upon the character of the veneers.

The platens are heated with steam at preferably 80 to 100 poundspressure, at a te1nperature somewhat exceeding 100 degrees Fahrenheitabove the boiling point of water at atmospheric pressure, whereby themoisture is driven out by the force of its own expansion. As the platensrecede, the opposite faces of the veneers are exposed to the inrushingair which absorbs the moisture which has been thus vaporized and alsotakes out some of the moisture from the wood itself. This action isgreatest at the edges of the sheet of veneer, and especially at the endwhich is in practice substantially iush with the end of the adjacentplatens.

When the driers are located in a large room surrounding the entireapparatus and the space adjacent the same for access by the attendants,the inrushing air between the platens under such condition is very dry,and the excessively rapid drying at the end causes a considerable lossthrough splitting. With the driers inclosed within a comparatively smallspace as above described, the air drawn in between the platens,especially for the initial portion of the drying action, becomes chargedwith moisture, and the excessive end drying is very much reduced, with aconsequent material reduction in loss through splitting of the veneer,the drying action being entirely completed while the casing remainsclosed from the external atmosphere.

It will be observed that by the process above described, the moistureissues from the wood through its vaporization at a high degree of heat,rather than by being absorbed by the action of heated air entering itspores. The action of the moistened air in the drying casing or chamberis not so much to keep the pores of the wood open to permit theremaining moisture to escape as to prevent too rapid drying andconsequent splitting of the veneer on the exposed end during thebreathing movements of the heated platens.

As the amount of moisture absorbed by the air surrounding the platensand the in terposed veneers increases as the drying operation continues,it will be observed that this volume of air acts progressively inretarding the extraction of moisture as the drying operation approachescompletion.

Having thus set forth the nature of the invention, what I claim hereinis 1. In a veneer drying apparatus, in combination, a plurality ofspaced platens having parallel fiat faces, means for heating them, aclosed casing constructed with insulated walls closely embracing andaHording a housing for said platens and having a wall permanently inclose proximity to edges of and unobstructed spaces between saidplatens, and means for affording direct acceslslto said spaces from theexterior of said wa 2, In a drying apparatus, in combination,

means for supporting and applying heat to the objects to be dried, aclosed casing provided with detachable insulated Walls closely embracingand aiiording a housing for the same, and means applied to said easingand movable independently of said detachable Walls for aiording accessto said objects.

3. In a veneer drying apparatus, in combination, a plurality of platensmounted for substantially rectilinear movement toward and from eachother, means for heating said platens and for moving them toward andfrom each other, a closed casing provided with insulated walls housingsaid platens, and means in permanent alinement with and adapted toprovide access simultaneously to said platens at unobstructed edgesthereof from the exterior or said casing.

4f. In a drying apparatus, in combination, a series of platens, meansfor heating the same, a closed casing provided with insulated Wallshousing said series of platens, means for providing access to saidplatens at the edges thereof, and means, including hydraulic cylindersdisposed external to said casing, for moving said platens toward andfrom each other.

5. In a drying apparatus, in combination,

a series of platens, means for heating the same, means for moving themtoward and away from each other, a frame for inclosing said series ofplatens, insulating plates detachably secured to said frame and togetherail'ording a closed housing for said platens, and means adjacent theedges of 3 and adapted to provide access to said platens from theexterior of the casing.

6. In a drying apparatus, in combination,

a series of platens, means for heating the same, means for moving themtoward and 4 from each other, a main frame embracing said platens andthe means for heating and moving them, an auxiliary frame, andinsulating plates detachably secured to said auxiliary iframe andtogether aiording a 4 closed housing closely embracing said platens andtheir heating means.

In testimony whereof, I have signed my name to this specification, inthe presence off two subscribing Witnesses.

FRANK BISHOP. l/Vitnesses:

A. C. NIBLAGK, R. W. Hoovnn.

Copies o3.' this patent may be obtained for five cents each, byaddressing the Commissioner o! Patents,

Washington, D. G."

